21st March 2024

Elderly

Elderly patients are often subject to polypharmacy due to multiple co-morbidities. They are also more susceptible to side effects and adverse drug reactions in part because of their ageing physiology. Regular review and rationalisation of medication is therefore important for patient safety. The British National Formulary (BNF) guidelines recommend the use of STOPP (Screening Tool of Older Persons’ Prescriptions) and START (Screening Tool to Alert to Right Treatment) criteria. This was devised by experts to aid doctors prescribing for the elderly with the view to improve medication appropriateness and reduction of adverse effects. The pertinent points are summarised below.

Cardiovascular system

Several agents have been implicated in the STOPP/START criteria relating to the cardiovascular system. For the treatment of oedema with limited evidence of organ dysfunction, one should consider non-pharmacological treatments such as compression bandages and leg elevation. Loop diuretics should not be used for dependent oedema or as a first-line agent for hypertension.

ACE inhibitors (ACEi) are encouraged for systolic heart failure or coronary heart disease but should be stopped in those with hyperkalaemia. If co-prescribed with potassium sparring agents such as spironolactone, eplerenone and amiloride one must monitor potassium regularly. Beta-blockers and calcium channel blockers (CCBs) are encouraged for stable angina, although both dihydropyridines and non-dihydropyridine CCBs may exacerbate heart failure. Non-selective beta antagonists are best avoided in patients with bradycardia and obstructive airway disease. Thiazide diuretics act on the sodium/chloride co-transporter and have a propensity to cause electrolyte disturbances particularly hyponatraemia, hypokalaemia, hypercalcaemia and can exacerbate gout. Alpha blockers such as doxazosin and prazosin should be stopped in those with orthostatic hypotension or micturition syncope.

Amiodarone is a class III anti-arrhythmic which blocks potassium channels. It has a long half-life with significant adverse effects including hepatoxicity, lung fibrosis and thyroid dysfunction. It is effective in the treatment of supraventricular tachyarrhythmias however, in the elderly, other agents should be considered first-line if possible following review.

Digoxin works by inhibiting the sodium/potassium pump. It must be monitored with the levels taken usually 6 hours after the most recent dose. There is limited evidence for digoxin use in those with preserved ejection fraction and in accordance with the STOPP criteria should be stopped.  As well as this, cessation should occur if there is significant renal impairment (eGFR <30ml/min/1.73m^2) as it can lead to toxicity.

Statins are recommended for patients with known coronary heart disease, QRISK scores >10% and in patients with diabetes or chronic kidney disease of eGFR <60min/1.73m^2.

Hypertension

Antihypertensives should only be used if blood pressure is consistently greater than 140 / 90 mmHg. In those >80 years of age, a higher range of 150 / 90 mmHg is acceptable unless there is evidence of diabetes. Centrally acting antihypertensives (methyldopa, clonidine and moxonidine) are not as well tolerated by the elderly.

Gastrointestinal system

Metoclopramide is a dopamine receptor antagonist which can worsen Parkinson’s disease and must be avoided. Domperidone must be used cautiously in those with prolonged QTc and those co-prescribed CYP3A4 inhibitors (clarithromycin and ketoconazole). It is also contraindicated in those with underlying cardiac disease including congestive heart failure because it increases the risk of arrhythmias.

Proton pump inhibitors (PPI) are indicated for uncomplicated peptic ulcer disease and can be used in cases of severe oesophagitis or oesophageal strictures requiring dilation. PPIs are also used for those at risk of bleeding e.g. on antiplatelets, selective serotonin reuptake inhibitors (SSRIs), venlafaxine, corticosteroids and non-steroidal anti-inflammatories (NSAIDs). In the elderly, simple antacids are not for long term use as these do not prevent symptoms but rather only provide temporary relief. Lifestyle advice is encouraged; mainly promoting avoidance of smoking, coffee, chocolate and fatty foods.

In the elderly population with constipation, all constipating agents should be avoided where possible. This includes anticholinergic drugs, oral iron, opioids, verapamil and aluminium antacids. Equally, in cases of diarrhoea, it is important to avoid exacerbating factors such as antimotility drugs, unnecessary PPI (C. difficile risk) and broad-spectrum antibiotics.

Respiratory system

For those with uncontrolled mild to moderate COPD who are on salbutamol, there should be an assessment of the following asthmatic features, previous secure diagnosis of asthma or atopy, a higher eosinophil count, substantial variation in FEV1 and/or substantial variation in peak expiratory flow (at least 20%). If features are present a long acting beta agonist (LABA) and inhaled corticosteroids (ICS) should be given. If no features are present, a LABA and LAMA can be given.

The stop criteria highlights considering cessation of anti-muscarinic bronchodilators (ipratropium and tiotropium) in those with a history of narrow angle glaucoma as it may exacerbate glaucoma and in those with bladder outflow obstruction as it may lead to urinary retention.

Inhaled corticosteroids are preferred to systemic corticosteroids for the maintenance of COPD due to the unnecessary exposure to long term systemic side effects. Theophylline with its narrow therapeutic index should not be used as monotherapy for asthma or COPD as there are safer and more effective alternatives.

Anticoagulants and antiplatelets

The use of anticoagulants and antiplatelets must be weighed with the bleeding risk. Any concurrent risk factors such as uncontrolled hypertension, bleeding diathesis and recent non-trivial spontaneous bleeding should be taken into account with potentially stopping agents (aspirin, clopidogrel, dipyridamole, warfarin and more).

Anticoagulation for deep vein thrombus and pulmonary embolism (without continuing provoking risk factors) does not need to be continued for more than 6 months and 12 months respectively as there is no proven added benefit. Direct thrombin inhibitors (dabigatran) and factor Xa inhibitors (apixaban) are mainly renally excreted and thus if the eGFR levels are below 30 and 15, the drugs should be stopped respectively.

In those aged 65 and above with atrial fibrillation the CHA2DVASc and HAS-BLED scores are used to assess commencing anticoagulation and bleeding risk. The ORBIT tool is now recommended by NICE in place of the HAS-BLED tool to identify bleeding risk to help make decisions on anticoagulation. It is as follows:

Nervous system

Tricyclic antidepressants particularly dosulepin should be stopped in those with dementia (risk of worsening cognitive impairment), glaucoma (can worsen), cardiac conductive abnormalities (pro-arrhythmic effects) or prior history of constipation or urinary retention. One should be cautious in prescribing benzodiazepines and hypnotics if a fall has occurred in the past 3 months or if the patient has an acute or chronic respiratory failure (pO2 < 8.0 kPa or PCO2 > 6.5 kPa).

Antipsychotics have a wide range of adverse effects from extra-pyramidal side effects with gait disturbances to urinary incontinence and confusion. The necessity of these drugs should be weighed with the adverse effects, particularly when used long term. With the risk of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) from selective serotonin re-uptake inhibitors (SSRIs), stopping these agents would be appropriate in those with significant hyponatraemia (below 130 mmol/l). Citalopram and escitalopram are causes of QT-interval prolongation and thus must be monitored.

Anticholinergic agents have been linked to impaired cognition and physical decline in the elderly. These drugs can manifest with a wide spectrum of symptoms affecting the central nervous system (delirium, agitation and hallucinations) and peripheral nervous system (blurred vision, photophobia and reduced gastrointestinal peristalsis). The STOPP criteria highlights that these drugs should be stopped in those with a history of persistent bradycardia, heart block or recurrent unexplained syncope.

Anticholinergic burden scale

The anticholinergic burden scale lists the anticholinergic activity of a variety of drugs. A total score of three or more is considered clinically significant.

References

• O’Mahony D, STOPP (Screening Tool of Older Persons’ Prescriptions) and START (Screening Tool to Alert to Right Treatment) are explicit criteria that facilitate medication review in multi-morbid older people in most clinical settings. (2015)
• NHS Scotland, Polypharmacy Guidance (March 2015) <https://www.sehd.scot.nhs.uk/publications/dc20150415polypharmacy.pdf>